1. Field of the Invention
The instant disclosure relates to an electrophoretic display; in particular, to a method of establishing look-up table for an electrophoretic display and device.
2. Description of Related Art
The invention of cathode-ray tube starts the progress of display device. However, the cathode-ray tube is gradually replaced by the liquid-crystal display, the light-emitting diode display, or the plasma display, because the cathode-ray tube has a huge size and has larger power consumption. The cathode-ray tube, the light-emitting diode display, and the plasma display are self-light emitting displays, and the self-light emitting displays consume more electrical power for operation. The liquid-crystal display is a see-through display, and alignment of the liquid-crystals in the liquid-crystal display can be controlled by driving voltages. The liquid-crystal display can display images by controlling whether a light source of the liquid-crystal display penetrates the liquid-crystals.
Comparing to the self-light emitting display and liquid-crystal display, a reflective display reflects ambient light for display images. Therefore, the reflective display saves more electrical power. Currently, the electrophoretic display is a well-developed reflective display. The electrophoretic display usually has microcapsules, and the microcapsules can be controlled by driving voltage generated by driving circuit in order to make the electrophoretic display show images.
However, the driving waveforms generated by the driving circuit usually have the capability of maintaining the stability and the clarity of images, and the driving waveforms have to clear the previous image and adjust the refresh rate. Therefore, the driving waveforms are usually stored in a predetermined look-up table. The look-up table of driving waveforms is usually complex, and a large storage capacity may be needed to store the look-up table.
Traditionally, driving waveforms are divided by a predetermined unit time (e.g. 20 millisecond), and voltage values of waveform in each unit time is stored in the look-up table in time sequence. Then, a clock-controlled circuit reads the voltage values stored in the look-up table in time sequence, and the driving circuit can generate driving waveforms according to the voltage values from the look-up table.
Considering the display performance, a driving waveform usually includes some shaking pulses, reset pulses, and driving pulses. The shaking pulses are used to decrease the inertness of microcapsules. The reset pulses are used to increase the reproduction rate of the optical state for the pixel represented by microcapsules. The driving pulses can be a voltage with zero amplitude. However, when the pixels of the electrophoretic display or the colors displayed by the electrophoretic display are smaller in certain applications, a traditional look-up table may occupy unnecessary storage capacity or just complicate the design of the electrophoretic display.